Process of hydrolyzing oils and fats



April 18, 1939. G. w. EISENLOHR PROCESS OF HYDROLYZI'NG OILS AND FATSFiled Nov. 24, 1956 2 Sheets-Sheet 1 April 18, 1939- G. w. EISENLOHR2,154,835

PROCESS OF HYDROLYZING OILS AND FATS Filed Nov. 24, 1956 2 Sheets-Sheet2 Patented Apr. 18, 1939 UNITED STATES PATENT OFFICE Gustav W.Eise'nlohr, Wyoming, Ohio, assignor to The M. Werk Company, St. Bernard,Ohio, a

corporation oil Ohio Application November 24, 1936, Serial No. 112,531

6 Claims.

This invention relates to the hydrolysis of oils and fats andparticularly to a process or processes vfor hydrolyzing oils and fatsand to a -machine for carrying on said process.

The saponication or hydrolysis processes and mechanical devices used inworking said processes at the present time are classified by Lewkowitschin his Chemical Technology and Analysis of Oils, Fatsand Waxes, sixthedition, volume 3, page 216, as follows:

(1) Aqueous saponication.

(2) Saponication with vthe assistance of bases.

(3) Sulphuric acid saponication. Acid saponication.

(4) The mixed process.

(5) Saponification by means of sulpho-com- -pounds.

The processes above referred to are all well known stearine candles,soaps and glycerin. In all of these processes the batch method isemployed, that is to say a certain definite quantity of oil or fat issaponied or hydrolyzed in a single batch or operation. Likewise, inpractically all of the processes at this time commonly employed in thehydrolysis of oils and fats certain chemicals or reagents are used.Thus, in the saponification by means of sulpho compounds, commonly knownas the Twitchell process, or in modifications thereof, fat and water aretreated with a Twitchell reagent or modified reagent, (commonly called asaponifler) and sulphuric acid and boiled with open steam for upwards tothirty hours. This process is usually carried on in a Wooden tub. Thematerial darkens during the process the fatty acids therein undergoingdiscoloration. On completion of the hydrolysis the reagent and thesulphuric acid go into the sweet water or glycerine water and must betreated by lime neutralization and ltration to get rid of the reagentand the sulphuric acid. It has been found in practice that Where 'achemical reagent is omitted as in some of the digester or autoclavemethods, the results are unsatisfactory due to additional length of timenecessary to produce a satisfactory or practical hydrolysis orsplitting. In addition, even where aqueous saponication is carried on bythe digester or autoclave method, without the use of any saponiers,reagents or other chemical auxiliaries, the method necessarily continesitself to a batch or to a quantity limited to the size of a practicaldigester or autoclave.

The present process dispenses with all chemiin vthe manufacture ofstearic acid,

(ci. aco-sis) cal reagents entirely, the process depending for itsresults on physical as opposed to any chemical means, the purpose of theprocess being to exert high pressure on a mixture of water and arelatively small amount of fat indirectly heated to a high temperatureas against exerting pressure on a mass in an autoclave Where the mass isdirectly heated by either high pressure or superheated steam in thepresence of a catalytic agent.

Although processes for the hydrolization of fats have been proposedheretofore as disclosed by Patent 11,766, these prior methods do notrind commercial application at the present time for several reasons,chiey because of the time involved, the undesirable properties impartedto the product obtained, and the operating conditions as to temperatureand pressure together with lack of uniformity in these conditions withresults varying from incomplete hydrolization to destruction of theresultant products.

This invention has as an object an improved method for the continuoushydrolyzing of fats which results in complete hydrolization in markedlyless time than the methods previously proposed and without thediscoloration of the product and other disadvantages attending the priorpractice. inafter.

The above and other objects are accomplished by the inventionhereinafter described in connection with the accompanying drawings onwhich the preferred operating conditions are indicated and in which,

Fig. I is a plan view of the entire machine.

Fig. II is a side elevational view of the entire machine.

Fig. III is a cross-sectional view of the reaction coil and shellenclosing same.

Fig. IV is a top view showing the return Ls of the reaction coil and theposition of the resistance units.

Other objects will appear here- Fig. V isa side elevational view of thereturn and is heated by means of heating coils 2 located in the supplytank. However, it is to be under-l mate mixture of the fat and water becreated.

i glycerin in the water.

-For instance, I have found that a slow boiling with a steam coilproduces enough agitationto insure good mixing. In short, any mechanicalmeans` of producing a good mixtureof the proper proportions of fat andwater can be made use of. However, in any case'air should be excluded asmuch as possible in the supply tank or in preparing the mixture. Thewater used should preferably be distilled. From the supply tank or tanksthis mixture of fat and water is pumped by means of an hydraulic or anyother kind of pressure pump, (IP-VD) or by any other mechanical meansfrom the supply tank through the line 2| and through the pressure lineI9 at I'I to the reaction coil (Fig. III) enclosed in the cylindricalshell I I) (Figs. I, II and III), the reaction coil being surrounded bysuperheated steam which enters the shell at 5 and has its outlet at 6.By this means vthe mixture in the reaction coil is maintained at asubstantially uniform temperature throughout the length of the coil.This shell need not at any time be under more than a nominal pressure ofsay, 10 to 20 pounds. The steam is superheated by any of the well knownmethods to fromy 300 to 350 C. so as to maintain a temperature of from260 to 320 C. on the inside of reaction coil. While I have designatedsuperheated steam it is obviousthat any heat may be used to bring themixture in the reaction coil to the desired temperature such as a hotoil bath, hot air, or any other heat interchange system or means. Thepressure in they said reaction coil is built up by means of resistanceunits 9 (for detail see Fig. IV, 25 and 26) which tend to maintain apressure of from 2500`to 3500 pounds on the heated fat to be split.

This pressure is further regulated by means ofk the pressure regulatingvalves 8. From the pressure or reaction coil the mixture,v which is nowa fatty acid and a glycerin solution commonly called sweet water, isforced through the outlet of the pressure line leading from the reactioncoil to an evaporator coil I3 located in the conical bottom of receivingtanks I2. Some heat transfer occurs to and through the tubes or pipesconstituting the evaporator coil, concentrating the sweet water whichhas separated out in the conical bottoms I2 and correspondingly coolingthe fatty acid and sweet water mixture inside the coil I3. 'I'histransferred heat also has a tendeny to break up any emulsion which maystill persist at this stage, i. e'. when the mixture goes into thereceiving tanks after passing through the expansion and condensingvessel II. From the coil I3 the fatty acid and sweet waterl mixture isforced through a pipe 30 to and through a condenser shown as II in Figs.I and II, which is maintained at a temperature so as tocool the mixtureto approximately 80 C. The pressure is released to approximately 50pounds in' the condensing vessel II and is fully released in thereceiving tank I2 into which the mixture of fatty acids` and sweet wateris then forced through pipe line 40. The release of the pressure in thisash condenser tank II -causes part of the water to be instantlytransformed into steam. By regulating the temperautre of the coolingwater the amount of condensate'is controlled, thus regulating theconcentration of The sweet water is then conveniently drawn off throughoutlet I6 from the bottom of the'conical receivers I2 and the fattyacids are removed through outlet I5. There are also connected to theclosed receivers I2, by means of pipe 50, conveniently located in thecovers of said receiving tanks, the vapor collecting tanks I4. Thesevapor collecting tanks are ordinary open tanks containing water, andkept practically full at all times. The connecting pipes 50 are soarranged that the escaping vapors bubbling up through the sweet waterand fattyv acids pass through these pipes and into the vapor collectingtanks, thus eliminating losses in the glycerin recovery carried olf byand in the escaping vapors to the vapor collecting tank. 'y'

A pipe line 60 is connected with the reaction coil (AA) this pipe lineleading back to supply tank 3. A safety'valve 'I is placed in the line60 to relieve excess pressure in the reaction coil, the mixture in thereaction coil in such event flowing back into the supply tank.

The hydrOlyzation or -splitting occurs practically instantaneously inthe 4pressure coil (for detail see cross-section view Fig. III) wherethe mixture of fat and water are subjected to from 2500 to 3,500 poundspressure and from 260 to 320 C. of indirect heat. While I have specifieddesired pressures and temperatures, it is under-- l2li, for instance1/64 inch in diameter (see detail drawing Fig. IV). However, I do notwish to be limited to these perforated discs as tothe manner in whichthe pressure is built up, as this can be accomplished in a variety ofWays, such as alternate pressure vbafiles. in the reaction coil or bythe use of small diameter tubing to form the reaction coil or by anymeans which tends to retard or resist the free flow of the mixturethrough the pipes constituting the reaction coil. I have providedconventional gatevalves 4 in the pipes or lines 2|, 30 and 40 toregulate or shut off theflow. Similar' valves may be inserted in otherlines as desired.

The present process consists essentially of sub- The process andapparatus produce fatty acids as light as the original oil, fat ortallow used in the mixture, the result being accomplished by excludingair at all stages in the process and operations and particularly in thesupply tanks, condenser and receiving tanks.`

Having described my invention what I claim as new and desire to secureby United States Letters Patent is:

1. A process which comprises hydrolyzing instantaneously a continuouslyflowing stream of. fatty -material `which comprises continuously forcingunder at least 2500 pounds pressure through a reaction coil a mixturecomprising water and a hydrolyzable fatty material in substantial amountbut in amount substantially less than the amount of water, heating'thecoil by indirect heating means to a, temperature which maintains thematerial flowing therethrough at a substantially uniform temperature inthe range of 260 to 320 C., continuously ilowing the hydroiyzed materialfrom the reaction coil, condensing said material, and separating thefatty acids from the glycerin water.

2. A process for hydrolyzing fatty material which comprisespreliminarily boiling a mixture comprising water and a hydrolizablefatty material in substantial amount but in amount substantially lessthan the amount of water, passing the mixture under at least 2500 poundspressure through a reaction coil, maintaining the material in the coilat a temperature of range 260 to 320 C., passing the liquid mixture fromthe reaction coil to an expansion and condensing vessel, releasing thepressure in said condensing vessel, and passing the mixture from saidvessel to a. receiving tank, and separating the fatty acids from theglycerin water.

3. A process for hydrolyzing fatty material which comprisespreliminarlly boiling under conditions excluding air a mixturecomprising water and a hydrolizable fatty material in substantial amountbut in amount substantially less than the amount of water, passing themixture under at least 2500 pounds pressure through a reaction coil,maintaining the material in the coil throughout its length atsubstantially uniform temperature within the range of 260 to 320 C.;passing the liquid mixture from the reaction coil to a condensing resse!with exclusion ci air, releasing the pressure in said condensing vesseltc transform a portion of the water into steam, the fluid mixtureilowing continuously from said reaction coil into said vesseL passingthe mixture from said vessel to a receiving tank with exclusion of air,and separating the fatty acids from the glycerin water.

-4. The process set forth fin claim 3 in which said mixture containsabout one part oi"V fat and two parts of water. t

5. A process for hydrolyzing fatty material, the steps which comprisepassing a mixture comprising water and said material under at least2,500 pounds pressure through a reaction coil in which the mixturethroughout the length of the coil is maintained through indirect heat ata substantially uniform temperature within the range of 260 to 320 C; bycontacting the conduit forming the coil with heating vapor which ilowsthrough. and illls the spaces between the separate coils of the reactioncoil and which ilows previously heated from an inlet to a separateoutlet through a conilned space surrounding the coil, passing the liquidmixture from the reaction coil to a condensing vessel and therereleasing the pressure to transform a portion of the water into steam,the iluid mixture flowingcontinuously from said reaction coil into saidvessel, and passing the mixture from said vessel to a receiving tank,`and separating the fatty acids from the glycerin water.

6. The process set forth ln claim 5 in which the pressure in saidcondensing vessel is released to approximately pounds and thetemperature of the vessel is maintained at approximately C,

GUSTAV' W. EIBENIQHR.

